This common standard contains (3) surface notches at depths of0.008",0.020", and0.040". Notch width typically0.004" to0.005", with other widths possible. Notch depths are engraved on one edge; serial number and alloy on the other. NIST traceable. Available in multiple alloys, including several hard-to-find materials.
• Made from Copper 110.
• Fitted wooden storage case optional...see above.